310 research outputs found
多価不飽和脂肪酸を2位に結合するホスファチジルコリンの炭素アナローグの合成
Carbon analogues of Phosphatidylcholines having linoleic or arachidonic acid at the 2-position were synthesized. The synthetic route involves conversion of the polyunsaturated fatty acid iodination. The derivatives were converted to diols by LiAIH4 reduction and submitted to lipase-catalyzed monostearoylation in isopropylether. The mono-ester was converted to phoshatidylcholines by the usual phosphodiester synthesis.自然界に広く存在するホスフォリパーゼA2はグリセロリン脂質の2位のエステル結合を選択的に切断する酵素であり,消化,アラキドン酸カスケードの起動,リン脂質過酸化物の代謝等,生理作用に広く関わっている。本研究ではホスフォリパーゼA2の基質ミメテイックとしてホスファチジルコリンの2位エステル結合が炭素-炭素結合に置き換わった化合物をアラキドン酸とステアリン酸を出発原料としてリパーゼ触媒によるアシル化反応及び有機化学反応によって合成した
A Synthesis Phosphatidylinositol Bearing Arachildonic acid
Phosphatidylinositol bearing arachidonoyl group at sn-2 position was synthesized through preparation of protected myo-inositol, chemoenzymatic synthesis of an optically active lysophosphatidylcholine, introduction of an optically active sn-2 hydroxyl group, phospholipase D-assisted synthesis of a phosphatidic acid, and trisopropylbenzene sulfonylchloride assisted eaterification of the acid with the protected myo-inositol; as a final step.ホスファチジルイノシトールは,細胞外からのシグナルが細胞膜中の特異的受容体に結合する事により遊離される情報伝達物質の前駆体である.一般にそのグリセロール骨格のsn-2位には高度不飽和脂肪酸が,特にアラキドン酸が結合していることが知られている.本研究では,そのようなアラキドン酸結合ホスファチジルイノシトールの簡便な合成法を酵素的,化学的手法を用いる事により位置選択的に合成する事に成功した
Influences of the Presence of a Tall Grounded Strike Object and an Upward Connecting Leader on Lightning Currents and Electromagnetic Fields
Electromagnetic Fields at the Top of a Tall Building Associated With Nearby Lightning Return Strokes
Successful esophageal bypass surgery in a patient with a large tracheoesophageal fistula following endotracheal stenting and chemoradiotherapy for advanced esophageal cancer: case report
A 63-year-old man with esophageal achalasia for more than 20 years complained of respiratory distress. He was admitted as an emergency to the referral hospital three months previously. Computed tomography revealed tracheobronchial stenosis due to advanced esophageal cancer with tracheal invasion. He underwent tracheobronchial stenting and chemoradiotherapy. A large tracheoesophageal fistula (TEF) developed after irradiation (18 Gy) and chemotherapy, and he was unable to eat. Thereafter, he was referred to our hospital, where we performed esophageal bypass surgery using a gastric conduit. A percutaneous cardiopulmonary support system was prepared due to the risk of airway obstruction during anesthesia. A small-diameter tracheal tube inserted into the stent achieved ordinary respiratory management. No anesthesia-related problems were encountered. Oral intake commenced on postoperative day 9. He was discharged on postoperative day 23 and was able to take in sustenance orally right up to the last moment of his life. Esophageal bypass under general anesthesia can be performed in patients with large TEF with sufficient preparation for anesthetic management
Low energy indium or gallium ion implantations to SiO2 thin films for development of novel catalysts
It has been demonstrated that indium (In) implanted silicon dioxide (SiO thin films catalyze a reaction of benzhydrol with acetylacetone. In this study, it is found that the threshold In ion incident energy for manifestation of the catalytic effect exists between 400 and 470 eV. Furthermore, a technique to implant gallium (Ga) to SiOfilms has been developed with highly controlled doses and injection energies for the formation of thin films that promote Ga catalysts. The efficiency of catalytic reactions by Ga implanted SiOthin films is yet to be improved. Unlike In implanted SiO2, the reason why no significant reaction was observed in the case of Ga implanted SiOfilms examined in this study seems that the Ga ion energy was so low that deposited surface Ga atoms should lack interactions with Si atoms for the manifestation of catalytic reaction. © 2014 The Surface Science Society of Japan.Satoru Yoshimura, Masato Kiuchi, Yoshihiro Nishimoto, Makoto Yasuda, Akio Baba, Satoshi Hamaguchi, Low Energy Indium or Gallium Ion Implantations to SiO2 Thin Films for Development of Novel Catalysts, e-Journal of Surface Science and Nanotechnology, 2014, Volume 12, Pages 197-202, Released April 26, 2014, Online ISSN 1348-0391, https://doi.org/10.1380/ejssnt.2014.197, https://www.jstage.jst.go.jp/article/ejssnt/12/0/12_197/_article/-char/e
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